Sunnystate said:
Great shot, it may need a bit of color adjustments. I am also experimenting on very humble scale with astrophotography. Do you mind to tell what kind of tracking mount do you use, 5min it is considered pretty long exposure at 200mm, and all seems to be pinpoint sharp, also looks like you have used pretty small aperture considering the star shapes what ISO if you don't mind to share?
Thanks,
Z.
Thanks for the feedback on the photo - I agree that the color is too red, I just never got around to fixing it .It's not a great photo, I was just excited at the time to be able to make out some structure
So, the mount that I used is a case of extreme overkill for 200mm. The mount is an MI-250 from a company that no longer exists. It was the entry level of the high end mounts, if that makes any sense. I bought the mount to be able to image at around 2000mm (which requires a high end mount), so I splurged on the mount but started on my learning curve with a manageable focal length.
You could get similar performance at 200mm from a mount which costs probably about 1/10 of what my mount cost. This photo was autoguided. Basically, I had a small refractor as a guidescope with a cheap CCD camera (I have a used Meade DSI-2), and I piggybacked the 20D on top of that. I only did a very simple polar alignment of the setup (literally, I eyeballed it, no polar scope or drift aligning). At 200mm with autoguiding, it wasn't critical for me to spend the time to do a very accurate polar alignment.
As for the ISO, I'll have to check when I get back to the PC where the original data is stored. Given that it was a 20D, my guess was 800-1600 ISO, but that's just a guess.
Dave